A series of US weather satellites controlled by the National Oceanic and Atmospheric Administration. Tiros 1, launched in April 1960, was the world's first weather satellite. It failed after 2.5 months, but during that time succeeded in sending back about 23 000 photographs from around the Earth. Tiros 9, launched into polar orbit in January 1965, recorded the first complete picture of the Earth's weather in 480 pictures taken during nine orbits. Two upgraded polar orbiters of the Tiros-N type operate together, insuring that the weather data for any region of the Earth are no more than six hours old. The main instrument on each is the advanced very high-resolution radiometer (AVHRR).